The present invention relates to valve devices having pressure regulators, pressure regulators, carriages, liquid ejecting apparatuses, and methods for manufacturing valve devices.
A pressure regulator disclosed in Japanese Laid-Open Patent Publication No. 2001-227656 is known as a pressure regulator for decreasing liquid pressure to a constant level.
As a conventional inkjet type printer, a type in which ink is supplied from an ink cartridge to a pressure damper, which is installed in a carriage, through an ink supply tube is known (for example, see Japanese Laid-Open Patent Publication No. 2003-343757). The ink is then sent from the pressure damper to a recording head, such that printing is performed. If a relatively large amount of ink is retained in the ink cartridge, the carriage carrying the ink cartridge becomes relatively heavy. The weight causes excessive load to a drive motor for the carriage. Thus, the aforementioned printer is formed as a so-called off-carriage type in which the ink cartridge is not installed in the carriage. The pressure damper, which is provided in the carriage, suppresses variation of the ink pressure caused by reciprocal movement of the carriage.
As another conventional inkjet type printer, a type having a sub-reservoir, which is installed in the carriage for supplying ink to the recording head, is known (for example, see Japanese Laid-Open Patent Publication NO. 2003-251820). The sub-reservoir temporarily retains ink. A main reservoir serving as an ink cartridge is provided in a cartridge holder arranged in the printer body. The main reservoir supplies ink to the sub reservoir through an ink supply tube.
However, in the conventional pressure regulator of the publication No. 2001-227656, a central portion of a circular diaphragm and a valve body are connected to each other by means of a shaft. In other words, a valve shaft is located at the central portion of the diaphragm. Therefore, the valve body is pressed by the central portion of the diaphragm. The force for pressing the valve body is thus restricted to the level corresponding to the surface area of the diaphragm. That is, the force exceeding the level corresponding to the pressure receiving area of the diaphragm cannot be produced. This makes it difficult to minimize the pressure regulator.
Further, a pressure receiving portion of the pressure regulator is formed by the circular diaphragm. Thus, when the pressure regulators are employed in a multiple number, loss of the surface area (ineffective surface area) becomes relatively large. It is thus difficult to employ the pressure regulators in a highly integrated manner.
If the aforementioned pressure regulator is deployed in the carriage of the conventional inkjet type printer of the aforementioned corresponding documents such that the ink pressure in a pressure chamber, which retains ink, is decreased to a predetermined level, the carriage must have a relatively large thickness. Therefore, the printer as a whole may become relatively large.